<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<style type="text/css">
div{
display:inline-block;
border: 1px solid green;
width: 50px;
height:50px;
background-color: lime;
}

.left{
float:left;
}
.right{
float:right;
}
p{
clear: both;
}


</style>
</head>
<body>
<div class="left">1-1</div>
<div class="right">1-2</div>
<div class="left">1-3</div>
<p></p>

<div class="right">2-1</div>
<div class="left">2-2</div>
<div class="right">2-3</div>


</body>
</html>